UPDATE 1-U.S. CFTC queries Brazil's Petrobras on trading activities

(Adds details on trading probes)

RIO DE JANEIRO, May 30 (Reuters) - Brazil’s Petrobras has received an information request from the U.S. Commodity Futures Trading Commission regarding its trading activities, the state-run oil firm said on Thursday, after prosecutors found evidence of fraud in deals with major traders.

In a securities filing, Petroleo Brasileiro SA, as the company is formally known, said the U.S. regulator requested information on trading activities that are currently the target of “Operation Car Wash,” an investigation by Brazilian prosecutors that has uncovered billions of dollars in bribes.

In December, prosecutors said employees in Petrobras’ oil trading division accepted tens of millions of dollars in kickbacks from 2011 to 2014 from intermediaries connected to the world’s largest commodities traders, including Vitol SA , Glencore Plc and Trafigura AG.

The U.S. Federal Bureau of Investigation has joined the probe, and an employee at Petrobras’ Houston office, who was fired when an indictment came to light, is now cooperating with prosecutors in New York, according to documents.

“Petrobras ... was contacted by the U.S. Commodity Futures Trading Commission (CFTC) with information requests regarding certain trading activities that are the target of Operation Car Wash,” the company said on Thursday.

Glencore and Trafigura have declined to comment on the investigation. Vitol has said it has a “zero tolerance” policy with respect to bribery and corruption and that it is cooperating with authorities.

The CFTC disclosure comes amid a rocky week for Petrobras.

On Tuesday, a Brazilian Supreme Court justice suspended the $8.6 billion sale of a pipeline network to Engie SA in a decision that could jeopardize tens of billions of dollars in additional sales by the indebted Petrobras. On Thursday, another court suspended the sale of a fertilizer unit. (Reporting by Gram Slattery; Additional reporting by Luciano Costa in Sao Paulo; Editing by Chizu Nomiyama and Jeffrey Benkoe)